1. Field of the Invention
The described technology relates generally to an organic light emitting device that improves a low gray color representation capability.
2. Description of the Related Art
An organic light emitting diode display includes two electrodes and an organic emission layer interposed therebetween, wherein electrons injected from a cathode that is one electrode and holes injected from an anode that is another electrode are bonded to each other in the organic emission layer to form excitons, and light is emitted while the excitons discharge energy.
In a contemporary high efficiency organic light emitting device, when element performance is improved such that a driving current value of the organic light emitting device is more than an initial threshold value, emission efficiency of the element is suddenly increased in a low current application region such that unstable color expression of the low gray region is generated.
When controlling a low brightness region of the organic light emitting device by the current, the current efficiency is suddenly better such that a deviation of the driving current of the thin film transistor (TFT) appears as a brightness deviation. Particularly, color non-uniformity in the low brightness region is generated in the high efficiency organic light emitting device and is frequently generated in the green organic light emitting element.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.